79NOOTROPIC EFFICACY OF EUPHORBIA THYMIFOLIA LINN PHYTOSTEROL ON MICEEuphorbia thymifolia Linn (Family-Euphorbiaceae) is a commonly occurring annual herb found in waste lands and along roadsides under humid condition. Preliminary studies showed antianxiety and antidepressant property of E. thymifolia total sterol (ETTS) which drives to assessment of neurorejuvenating activity as ETTS may probably protect against dementia or can slow the progression of dementia. The present study attempts to evaluate nootropic effect of ETTS by testing its effect on exteroceptive, interoceptive and cognitive memory related behavior of mice.ETTS was isolated following standard procedure and percentage yield calculated. In acute toxicity study of ETTS on mice LD 50 found to be 283.00 mg/kg (i.p) and the dose range of 25, 50 and 75 mg/kg was selected for evaluation of nootropic activity. ETTS 75 mg/kg (P < 0.05) treated group showed significant reduction of response time, signifying active response maintenance compared to scopolamine induced amnesic response. Passive avoidance measured as step down latency (SDL) after 24 hrs of training was increased extreme significantly (P < 0.001) of all three doses of ETTS compared to scopolamine. Interoceptive behaviour was measured as transfer latency (TL) on elevated plus maze. ETTS sham dose levels non significant reduction of TL. ETTS at all three doses (25, 50, 75 mg/kg) showed significant reduction (P < 0.001) of TL against amne sic response of diazepam and scopolamine.Cognitive behavioural was assessed on lithium carbonate induced head twitches and haloperidol induced catalepsy. ETTS significantly reduced (P < 0.001) head twitches in all dosses but had non significant effect on haloperidol induced catalepsy. The present study indicated nootropic activity of ETTS as it showed facilitatory effect on retention of acquired learning and enhanced spatial long term memory.Further investigations are required for confirmation of ETTS neurorejuvenating potential in the treatment of various cognitive disorders and its role in CNS neurotransmissionp_bigoniya2@hotmail.comResearch512015Euphorbia thymifolia Linn,Phytosterol,Nootropic,Memory,CognitivePapiya Bigoniya,Alok Kumar ShuklaDepartment of P.G. Pharmacology, Radharaman College of Pharmacy, Fatehpur Dobra, Ratibad, Bhopal- 462 002, M.P., India,Department of P.G. Pharmacology, Radharaman College of Pharmacy, Fatehpur Dobra, Ratibad, Bhopal- 462 002, M.P., India